Autism spectrum disorder (ASD) is a neurological developmental disorder that affected approximately 1 in 110 children in the United States in 2006, and its prevalence has risen rapidly in recent years. In view of increasingly unmet needs for autism care, more and more states have passed mandates requiring private insurers to provide autism insurance. However, little is known about actual changes in autism services use, costs and health benefits after such mandates take effect. More importantly, access barriers to autism care persist for privately insured autistic children despite autism mandates. Without timely study and informed policy measures to address persistent access barriers, the care of children with ASD may be jeopardized. Using a unique large multi-state private insurance claims database, this research will be: 1) the first study to use post- mandate private insurance claims data to measure actual changes in autism service use, costs and health benefits after autism insurance mandates; and 2) the first study to explore access barriers that persist despite autism mandates. The findings will: 1) help evaluate autism mandates based on actual changes rather than prospective projections; and 2) help decision makers design future autism mandates and identify the next essential steps following the passage of autism insurance mandates to further remove access barriers and better serve children with ASD.